Figure 1.

Bursting of hypoglossal motoneurons induced by NMDA or DHPG. (a) Under current clamp condition, steady bursting is evoked by 25 µM NMDA. Each depolarization wave comprises a cluster of action potentials. In the presence of Cd²⁺ (400 µM), bursting is suppressed (middle panel) but reinstated during washout (right panel). (b) Theta frequency bursting evoked by DHPG (25 µM) applied to a motoneuron voltage clamped at −60 mV. Bursts are observed as inward current (large downward deflections) with superimposed fast oscillations; for further details, see Sharifullina et al. (2005, 2008).